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Öğe A Novel Longline That Can Be Used By a Single Crew in the Aegean Sea: Solo Longline(Çanakkale Onsekiz Mart Üniversitesi, 2020) Kançoban, Cezmi; Akyol, OkanThis short paper presents an innovation on the use of a bottom longline with only a single crew on a fishing boat in the Aegean Sea. The mainline was 0.80 mm in diameter and 75 m in length, with branch lines of 0.45 mm in diameter and 70 cm in length. Distance between two adjacent branch lines was 7 m. The total duration of the operation, excluding soak time, was 35 minutes for a total of 40 hooks. Although this small prototype seems to succeed, larger versions may cause operational difficulties. Therefore, we suggest that further handling techniques should be developed in the future for challenging tasks such as baiting and solo using.Öğe Additional Record of Mediterranean Spearfish, Tetrapturus belone Rafinesque, 1810 (Istiophoridae) from Izmir Bay (Northern Aegean Sea)(Çanakkale Onsekiz Mart Üniversitesi, 2020) Akyol, OkanTetrapturus belone is endemic to the Mediterranean and it is more common in central parts. It is considered very rare in the Levant. On 20 October 2020, a specimen of Tetrapturus belone with 176 cm Lower Jaw Fork Length (LJFL) and weighing 26 kg was captured by a trammel net from the coast of Karantina Island, Urla at a depth of 11 m. This is the second record of the epipelagic T. belone entering the shallow waters of İzmir Bay, nine years after its first record in the same area. This ichthyologic note presents a new occurrence of the Mediterranean spearfish as an incidental catch from the small scale fishery in a certain coastal area of Urla, Izmir Bay.Öğe Additional Record of Sphoeroides pachygaster (Tetraodontidae) in the Aegean Sea (Fethiye, Turkey)(Çanakkale Onsekiz Mart Üniversitesi, 2020) Tüney Kızılkaya, İnci; Akyol, OkanSphoeroides pachygaster has been well-known in the Mediterranean since the first recorded from Balearic Islands in 1979, and then, it has rapidly reached to eastern Levantine. It is widely distributed throughout the Mediterranean, especially in Italian waters, including Strait of Sicily. However, it is still rare in the Turkish seas. A single specimen of the blunthead puffer, Sphoeroides pachygaster was caught by a commercial trammel netter off Göcek, Fethiye Bay at a depth of 125 m on 05 July 2020. This short note contributes to the ichthyofaunal richness of the Turkish Aegean Sea with an additional record of S. pachygaster.Öğe Age, growth, and reproductive season of bluefish (Pomatomus saltatrix) in the Marmara region, Turkey(Oxford Univ Press, 2007) Ceyhan, Tevfik; Akyol, Okan; Ayaz, Adnan; Juanes, FrancisBluefish (Pomatomus saltatrix) are distributed widely along the Turkish coasts, and are regularly captured, especially in the Sea of Marmara during their spawning migration to the Black Sea from the Mediterranean in spring and during their return migration south in early autumn. Age, growth, and reproductive season are reported. The ages of 1114 bluefish were determined from otoliths. The age groups ranged from 0 to III, and mean fork lengths (and weights) were 14.4 +/- 0.12 cm (38.2 +/- 1.02 g), 19.5 +/- 0.06 cm (93.7 +/- 0.86 g), 27.5 +/- 0.48 cm (238.5 +/- 11.3 g), and 33.3 +/- 0.50 cm (431.9 +/- 17.08 g) for each age group, respectively. The von Bertalanfly growth parameters were L infinity = 51 cm, K = 0.228, and t(o) = -1.26 y. The reproductive period, evaluated from gonadosomatic indices, began in early spring and extended until August.Öğe Akköy Lagünü’nde (Ege Denizi) Tül Iğrıpla Yakalanan Balık Tür Çeşitliliğine Mevsim ve Bazı Fiziko-Kimyasal Parametrelerin Etkileri(Çanakkale Onsekiz Mart Üniversitesi, 2021) Sağlam, Cemil; Akyol, OkanThe study was carried out monthly between 2014 and 2016 in Akköy Lagoon, Southern Aegean Sea. Experimental beach seine net was used to determine the species diversity in the lagoon. Fishing operations were carried out in triplicate at two different stations. Sea surface temperature (°C), salinity (‰), dissolved oxygen (mg.l-1) and pH were measured. Abundance, species richness (S) and Shannon (H) index values were computed to determine species diversity. A total of 1878 fish specimens from 17 species belonging to 9 families were captured by the beach seine net. The Mugilidae family with five species was represented by the highest catch rates among all the families. According to Canonical Correspondence Analysis (CCA), the diversities of fish species were strongly influenced by environmental parameters. Results indicated that Chelon ramada, Mugil cephalus and Chelon saliens were dominant in the winter and autumn and showed positive correlation with DO. Chelon auratus and Sparus aurata were dominant in the spring and Solea solea, Chelon labrosus, Lithognathus mormyrus, Sardina pilchardus, Boops boops, Zosterisessor ophiocephalus, Mullus spp. and Syngnathus spp. were dominant in the summer and showed positive correlation with SST, pH and salinity. Atherina boyeri, Aphanius fasciatus, Blennius spp. and Pomatoschistus spp. were present in all seasons.Öğe Capture of a Blue Shark Prionace glauca (Linnaeus, 1758) (Chondrichthyes: Charcharhinidae) by a Swordfish Longliner off Fethiye (Mediterranean Sea, Turkey)(Çanakkale Onsekiz Mart Üniversitesi, 2020) Akyol, Okan; Ceyhan, TevfikOn 25 December 2012, a specimen of Prionace glauca (Linnaeus, 1758) was caught by a swordfish longliner along with 9 swordfish together off Fethiye at a depth of 1200 m. The specimen caught was measured as TL and weighed (kg), and photographed. The specimen was 85 cm TL and 7 kg. According to the previous studies, blue sharks especially observed abundantly in northern Aegean Sea, and can be accepted very rare incidental catch from the Turkish coasts owing to weak presuppose of swordfish fishery. However, there is an important place of blue sharks in the global fin trade area. Therefore, population trend of this shark species is swift decreasing.Öğe Güney Ege Kıyıları (Türkiye) Uzatma Ağları Balıkçılığında Egzotik Türler ve Birim Çaba Başına Düşen Av (CPUE) Miktarları(Çanakkale Onsekiz Mart Üniversitesi, 2022) Akyol, Okan; Ceyhan, Tevfik; Düzbastılar, F. Ozan; Ertosluk, OkanThis study presents some exotic fish diversity and catch per unit effort values of exotic fish from gillnet fishery along the southern Aegean Sea. Lessepsian puffer fish (Lagocephalus sceleratus), lionfish (Pterois miles), squirrelfish (Sargocentron rubrum), rabbitfish (Siganus sp.) and a blue crab (Portunus segnis) were caught in the Aegean Sea. Rabbitfish and blue crab sell in the fish markets. Seasonally, the average CPUE of exotic fish was calculated to be 0.7 ± 0.3 kg.1000 m-1 in autumn in catch. This value indicated that it was 72 times lesser than the total seasonal CPUE.Öğe İzmir Körfezi (Ege Denizi) Lesepsiyen Balıkları(Çanakkale Onsekiz Mart Üniversitesi, 2023) Akyol, OkanTürkiye kıyılarından bildirilen yabancı balık türü sayısı 80'e ulaşırken, Ege Denizi kıyılarından bildirilen yabancı balık türü sayısı 44'tür. Diğer taraftan, İzmir Körfezi'nden bildirilen Lessepsiyen türü sayısı 15'tir. İzmir Körfezi'nden bildirilen Lessepsiyen balık türleri sırasıyla Saurida lessepsianus, Lagocephalus sceleratus, Siganus rivulatus, S. luridus, Scomberomorus commerson, Bregmaceros nectabanus, Champsodon vorax, Etrumeus golanii, Stephanolepis diaspros, Nemipterus randalli, Upeneus moluccensis, Hemiramphus far, Lutjanus argentimaculatus, Acanthopagrus bifasciatus, Pterois miles’tir. Bu derleme, Lessepsiyen türlerinin İzmir Körfezi'ndeki ticari balıkçılık faaliyetleri ile etkileşimini tartışmaktadır.Öğe Marmara Bölgesi' nde lüfer (Pomatomus saltatrix L., 1766) avcılığında kullanılan alamana ağları(2005) Ceyhan, Tevfik; Akyol, Okan; Ayaz, AdnanTürkiye denizlerinde geniş bir dağılım gösteren lüfer balıklarının avcılığında alamana ağları özellikle Marmara bölgesinde yoğun olarak kullanılmaktadır. Galsama ve fanyalı olarak iki gruba ayrılan alamana ağlarında, 21 Od/3-4 numara 46-64 mm TGB'nda, 21 Od/9-12 no 250-280 TGB'nda fanyalar kullanılmaktadır. Alamana ağlarının toplam uzunlukları 265 ila 660 m arasında değişmektedir. Donam faktörü (E) 0,5 ve 0,67 dır. Bir ünitede (yaprakta) tor ağın yüksekliği 60-120 göz, fanyanın ise 5,5-13,5 göz arasındadır. Bir takım alamana ağı 3 ila 8 ünite yükseklikte olabilmektedir.Öğe Maximum Size of Female Alexandria pompano Alectis alexandrina (Carangidae) in the Aegean Sea(Çanakkale Onsekiz Mart Üniversitesi, 2019) Akyol, Okan; Çoker, TulinA female specimen of Alectis alexandrina (710 mm TL) was caught on 15 July 2019 by an angler from the Bay of Gökova, Muğla, at a depth of 4 m. The specimen has the maximum size throughout the Turkish seas and it is fourth finding of this species for the Turkish Aegean SeaÖğe Occurrence of a Shoal of Bull Ray Aetomylaeus bovinus (Myliobatidae) Around a Sea-Cage Farm in İskenderun Bay (Türkiye, NE Mediterranean Sea)(Çanakkale Onsekiz Mart Üniversitesi, 2022) Akyol, Okan; Şen, Halil; Capapé, ChristianIn this study, a shoal of bull rays, Aetomylaeus bovinus (E. Geoffroy Saint-Hilaire, 1817), around a sea-cage fish farm in Iskenderun Bay, Turkey is reported. Such an aggregation is probably due to ontogenetic shift but may also be a factor of reproductive process as some pregnant females were observed. The number of individuals recorded, in all more than 25, shows that the species is still present in the area but needs a conservation plan due to its k-selected life-histories and potential for extinction.Öğe The encircling nets, used in bluefish (Pomatomus saltatrix L., 1766) fishery in Marmara Region(Ege Univ, 2005) Ceyhan, Tevfik; Akyol, Okan; Ayaz, AdnanEncircling nets, especially used densely in Marmara Region, are used for fishery of bluefish which are widely distributed in Turkish seas. Two types encircling nets (gill net and trammel net) are contained 210d/3-4 no thickness for fine-meshed net which have 46-64 mm mesh size, and 210d/9-12 no thickness for wide-meshed net which have 250-280 mm mesh size. Total lengths of the encircling nets are varied between 265 and 660 m. Hanging ratios (E) are between 0,5 and 0,67. Each layer of the nets are 60-120 mesh deep for finemeshed net and 5,5-13,5 mesh deep for wide-meshed net. Encicling nets can be formed 3-8 in layers.
